The present invention relates generally to a measurement tool adapted to measure the characteristics of at least one tubular structure within or extracted from a patient.
A coronary artery bypass graft (CABG) procedure is a common surgical procedure in which a graft vessel, such as a saphenous vein or mammary artery, is connected surgically to two target vessels. Traditionally, the diameter of the aorta, the diameter of the graft vessel, and the wall thickness of the graft vessel are not measured during CABG surgery. Instead, the surgeon visually inspects the diameter of the aorta and the diameter of the graft vessel, and disregards the wall thickness of the graft vessel. While such inspection may be adequate for suture-based anastomosis on a stopped heart, it may be inadequate when anastomotic connectors and deployment systems are used.
In one aspect of the invention, a single measurement tool is configured to measure at least two characteristics of a patient""s vasculature during a surgical procedure such as a coronary artery bypass graft procedure. By providing a single measurement tool to perform multiple measurements, the number of tools needed in the operating room during a surgical procedure is reduced, and space on the surgical tray is conserved.
In another aspect of the invention, the measurement tool may include an indentation defined in it, where that indentation has a radius of curvature. This indentation may be located at one end of the tool, or at another location on the tool. The indentation is placed against a tubular element such as the aorta or another artery to determine whether that tubular element has a diameter larger than or smaller than the radius of curvature of the indentation. Thus, it can be determined easily whether the diameter of the tubular element is larger than or smaller than a threshold value.
In another aspect of the invention, the measurement tool may include one or more first recesses. The first recesses each have a different width. By inflating or otherwise expanding a tubular structure extracted from a patient, that tubular element expands substantially to its in-vivo diameter. By attempting to place the tubular structure into a first recess, it can be determined whether its diameter is larger than, smaller than or substantially equal to the width of that first recess. Where multiple first recesses are provided, each has a different width, and the tubular structure can be placed successively into them in order to determine its diameter easily and quickly.
In another aspect of the invention, the measurement tool may include at least one second recess. A tubular structure extracted from a patient is allowed to remain in its natural state. That is, it is not inflated. When it is placed into a second recess, its walls are pushed together, and the lumen of the tubular structure is closed or substantially restricted. The walls of the tubular structure are substantially the same thickness, so the wall thickness measured by a second recess of a particular width is substantially half of the width of that second recess. By attempting to place the tubular structure into a second recess, it can be determined whether its wall thickness is larger than, smaller than or substantially equal to a particular value. Where multiple second recesses are provided, each has a different width, and the tubular structure can be placed successively into them in order to determine its wall thickness easily and quickly.